Fluoroelastomer composition

ABSTRACT

A fluoroelastomer composition which contains (a) a fluoroelastomer, (b) at least one member selected from the group consisting of bivalent metal oxide, bivalent metal hydroxide and mixture of bivalent metal oxide or metal hydroxide with metal salt of weak acid, (c) an aromatic polyhydroxy compound, and (d) a quaternary ammonium compound of imidazole or imidazoline, provides a fluoro-rubber having a low compression set and an excellent elastic property. The fluoroelastomer composition can be handled and processed with safety, and yet can be cured at a good cure rate, and has excellent storage properties. The cure rate of the composition is more accelerated by further addition of (e) water or a metal compound which produces water by reacting it with hydrogen fluoride.

United States Patent Kometani et al.

[ Feb. 4, 1975 FLUOROELASTOMER COMPOSITION [75] Inventors: Yutaka Kometani; Shun Koizumi,

both of Osaka; Takeshi Suzuki, Kyoto; Yasuyoshi Furukawa; Masayasu Tomoda; Kiyoichi Kondo, all of Osaka, all of Japan [73] Assignee: Daikin Kogyo Co., Ltd., Osaka,

Japan [22] Filed: Nov. 6, 1972 [2]] Appl. No.1 303,764

[30] Foreign Application Priority Data Nov. ll. 1971 Japan 46-90488 July 25. 1972 Japan 47-74848 [52] US. Cl 260/29.6 F, l77/l6l UZ,

117/161 UT, 260/29.6 MM, 260/29,6 MN,

260/29.6 ME, 260/80.77, 260/875 A [51] Int. Cl. C0 8 f 45/24 [58] Field ofSearch... 260/29.6 F, 87.5 A, 29.6 MM, 260/29.6 MN, 80.77

[56] References Cited UNITED STATES PATENTS 3,042,642 7/1962 DeMarco et al. 260/29.6 F

3,347,812 10/1967 DeMarco et al. 260/296 F Primary Examiner- Harold D. Anderson Attorney, Agent, or Firm-Clelle W. Upchurch [57] ABSTRACT A fluoroelastomer composition which contains (a) a fluoroelastomer, (b) at least one member selected from the group consisting of bivalent metal oxide, bivalent metal hydroxide and mixture of bivalent metal oxide or metal hydroxide with metal salt of weak acid, (c) an aromatic polyhydroxy compound, and (d) a quaternary ammonium compound of imidazole or imidazoline, provides a fluoro-rubber having a low compression set and an excellent elastic property. The fluoroelastomer composition can be handled and processed with safety, and yet can be cured at a good cure rate, and has excellent storage properties. The cure rate of the composition is more accelerated by further addition of (e) water or a metal compound which produces water by reacting it with hydrogen fluoride.

15 Claims, 1 Drawing Figure PATENTED 75 fiCo/rparaT/ve Exam 0A2 4 PO (In/nu fa) Time 1 FLUOROELASTOMER COMPOSITION BACKGROUND OF THE INVENTION The present invention relates to a novel fluoroelastomer composition. and more particularly to a fluoroelastomer composition suitable for preparing a fluororubber having a low compression set and an excellent elastic property.

The term fluoroelastomer" used herein means a highly fluorinated elastic copolymer and the term fluoro-rubber used herein means a cured copolymer obtained by curing the fluoro-elastomer.

A fluoro-rubber has an excellent heat resistance, a low temperature resistance and a chemical resistance and is useful for gaskets, sealants, diaphragmes, pipes and so on.

It is well known that fluoro-rubber is prepared by curing a fluoroelastomer in the presence of curing agent. The fluoro-rubber is required to have an excellent elastic property as well as a low compression set in the practical uses. In general, however, a fluoro-rubber prepared by curing a conventional composition tends to be inferior in compression set when the elastic property is guaranteed and, on the other hand, tends to reduce its elastic property when compression set is suppressed. Therefore, a fluoroelastomer composition which is able to provide a fluoro-rubber having an excellent elastic property in addition to a low compression set is earnestly desired.

Recently, various fluoroelastomer composition which can be cured to provide fluoro-rubbers having a low compression set have been proposed. These fluoroelastomer compositions are somewhat effective for reducing compression set, but it tends to have poor elastic property.

OBJECT OF THE INVENTION DESCRIPTION OF THE INVENTION from It has now been found that the above-mentioned ob-' i (1) R ll lfilii a R2 i wherein R is alkyl group having 1 to 20 carbon atoms, carbocyclic group, heterocyclic group or aralkyl group hvaing 7 to 20 carbon atoms, R is hydrogen, alkyl group having I to 12 carbon atoms, carbocyclic group, heterocyclicgroup, phenyl group, substituted phenyl group, aralkyl group having. 7 to 12 carbon atoms, alkoxyl group having 1 to 12 carbon atoms, benzyloxy group, hydroxyl group, carboxyl group, alkoxycarbonyl group, acyl group, benzoyl group or cyclohexylcarbonyl group, R is alkyl group having 1 to 20 carbon atoms or aralkyl group having 7 to 20 carbon atoms, R and R are hydrogen or lower alkyl group, A is alkylene group or phenylene group, B is alkylene group, and X is an anion such as halide ion, hydroxylate ion, alkoxylate ion, phenoxide ion, carboxylate ion, sulfonate ion, sulfate ion, sulfite ion and carbonate ion.

Further, by the addition of e) water or a metal compound which readily produces water by-reacting it with hydrogen fluoride, a cure rate of the composition can be accelerated without reducing the elastic property.

According to the present invention, there can be obtained a fluoro-rubber having excellent elastic properties such as modulus at 100 percent elongation, tensile strength, elongation and hardness, and low compression set at room or high temperature. For instance, when the fluoro-rubber of the invention instead of a conventional prior art fluoro-rubber is used for packing material in oil pressure machines under severe conditions, the repeated tightening of packing material is not required to prevent leaks of oil or gas, owing to the excellent properties of the fluoro-rubber according to the present invention, particularly low compression set and excellent elastic property.

Further, the fluoroelastomer composition of the invention can be handled and processed with safety. For instance, scorching seldom occurs during handling before cure. A complicated article can be readily prepared without any showing of back rind and other inferiorities because of the favorable flowability at the press cure. And yet, the composition of the invention can be cured with a good cure rate. Moreover, the composition of the invention has an advantage such as an excellent storability in comparison with conventional fluoroelastomer compositions.

in the present invention, it is essential that the above ((1) ingredient is quaternary ammonium compound of imidazole or imidazoline. Because, when imidazole or imidazoline per se or their salts of mineral acid or organic acid are employed, such excellent effects in handling or processing as obtained by the present invention can not be obtained.

The fluoroelastomer (a) ingredient of the invention, which is a highly fluorinated elastic copolymer, is, for instant, copolymer a of vinylidene fluoride and at least one fluoroolefin such as hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride,

perfluoro(methyl vinyl ether), perfluoro-(propyl vinyl ether), or the like.

vinylidene fluoride-hexafluoropropene copolymer and vinylidene fluoride-tetrafluoroethylene-hexafluoropropene terpolymer are preferably employed. In particular, it is interesting to use a copolymer which composition is in the ratio of vinylidene fluoride and hexafluoropropene being 92:8 to 66:34 by mole, or a terpolymer which composition is in rectangular area formed by the following four ratios of vinylidene fluoride, tetrafluoroethylene and hexafluoropropene being 85.725193, 59.7:5:35.3, 28:30:42 and 54:30:16 by mole, obtained by means of the process of suspension polymerization at low temperature.

Further, there may be effectively employed such polymers as obtained by copolymerizing a small amount of monomer such as vinyl compound, olefin, diene or a,B-ethylenically unsaturated carboxylic acid in addition to the above-mentioned monomers.

FIG. 1 is a graph showing a curing curve of a fluoroelastomer composition in the present invention and those of comparative fluoroelastomer composition.

.dimethylimidazolium Suitable examples of b) ingredient of the invention are bivalent metal oxides such as MgO, CaO, PbO or ZnO, metal hydroxides such as Mg(OH) Ca(OH) Pb(OH) or Zn(OH) and mixtures of the above metal oxides and/or metal hydroxides with metal salts which are formed from metals such as Ba, Na, K, Pb and Ca and weak acids such as stearic acid, benzoic acid, carbonic acid, oxalic acid and phosphorous acid.

Examples of (c) ingredient being aromatic polyhydroxy compounds are 2,2-bis(4-hydroxyphenyl)propane (Bisphenol A), 2,2-bis(4-hydroxyphenyl)perfluoropropane (Bisphenol AF), resorcinol, 1,3,5- trihydroxybenzene, l,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, l,6-dihydroxynaphthalene, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxystilbene, 2,6-dihydroxyanthracene. hydroquinone, catcchol, 2,- 2-bis(4-hydroxyphenyl)butane (Bisphenol B), 4,4- bis( 4-hydroxyphenyl )pentanoic acid, 2,2-bis( 4- hydroxyphenyl)tetrafluorodichloropropane, 4,4- dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl ketone, tri(4-hydroxyphenyl)methane, 3,3',5,5'- tetrachlorobisphenol A, 3,3,5,5'-tetrabromobisphenol A, and the like. Hydroquinone, Bisphenol A, Bisphenol B and Bisphenol AF are especially preferred, and alkali metal salts or alkaline earth metal salts of the above-mentioned aromatic polyhydroxy compounds may be also employed.

Examples of (d) ingredient being quaternary ammonium compound are as follows: l,3-dimethyl-2- heptylimidazolium iodide, l,3-dimethyl-2- nonylimidazolium iodide, 1,3-dimethyl-2- undecylimidazolium iodide, 1,3-dimethyl-2- heptadecylimidazolium chloride, 1,3-diethyl-2- heptadecylimidazolium chloride, l,3-dipropyl-2- heptadecylimidazolium chloride, l-dodecyl-3propylimidazolium iodide, l-dodecyl-2,3- dimethylimidazolium p-toluenesulfonate, l-3-didodecyl-2-methylimidazolium chloride, l-decyl-2,3- dimethylimidazolium iodide, l-decyl-2,3- dimethylimidazolium bromide, l-tetradecyl-2,3-

iodide, l-tetradecyl-2,3- dimethyl-imidazolium hydroxide, l-dodecyl-2-undecyl- 3-methylimidazolium sulfate, l,3-dihexadecyl-2- heptadecylimidazolium chloride, l-hydroxyethyl-Z- methyl-3-dodecylimidazolium p-toluenesulfonate, 1,3- didodecyl-2-phenylimidazolium chloride, l-dodecyl- 2,4-dimethyl-3-benzylimidazolium chloride, 1,3- dihexadecyl-2-phenyl-4-methylimidazolium chloride, l-vinyl-2-methyl-B-dodecylimidazolium chloride, 1- vinyl-2-methyl-3-hexadecylimidazolium chloride, 1- allyl-2-methy]-3:dodecylimidazolium chloride, l-(yaminopropyl)-2-methyl-3-dodecylimidazolium chloride, l-undecenyl-Z-octyl-3-ethylimidazolium bromide, l-eicosyl-2-eicosenyl-3-decylimidazolium bromide, ldodecyl-Z-methyl-3-benzylimidazolium chloride, 1,3- dibenzyl-2-methylimidazolium chloride, l,3-dibenzyl- 2-methylimidazolium hydroxide, l-benzyl-2-methyl-3- dodecylimidazolium chloride, l-dodecyl-2-methyl-3- benzylimidazolium chloride, l-butyl-2-heptyl-3- benzylimidazolium chloride, l-tetradecyl-2-methyl-3- benzylimidazolium bromide, l-dodecyl-2-phe nyl-3- benzylimidazolium bromide, l-benzyl-2-undecyl-3- methylimidazolium methylsufate, l-amyl-2-undecyl-3- benzylimidazolium bromide, l-dodecyl-2,5-dimethyl- 3-benzylimidazolium chloride, l-dodecyl-2-phenyl-3- benzyl-4-methylimidazolium bromide, 1-( 2 pyrimidinyl)-2,3-dimethylimidazolium chloride, 1.4-

butylene-bis[ l '-ethyl-3-dodecylimidazolium-(2')] dichloride, l ,4-phenylene-bis[ l '-dodecyl-3-benzyl-4- methylimidazolium-(2)] dichloride, l,4-phenylenebis-[ 1 '-dodecyl-3 '-dibenzyl-4'-methylimidazolium- (2')] dibromide, l,4-butylene-bis[2-ethyl-3-dodecyl 4'-methylimidazolium-( l')] dichloride. l.4-butylenebisl2'-methyl-3'-hydroxyethylimidazolium-( l)] dichloride. l,2-ethylene-bis[2,3-dimethylimidazolium- (1')] dichloride; l,3-dimethyl-2-heptylimidazolinium iodide, l,3-dimethyl-2-nonylimidazolinium iodide, 1,3-

dimethyl-Z-undecylimidazolinium iodide, 1,3- dimethyl-2-heptadecylimidazolinium chloride, l,3- diethyl-2-heptadecylimidazolinium chloride, 1,3-

dipropyl-2-heptadecylimidazolinium chloride, l-dodecyl-3-propylimidazolinium iodide, l-dodecyl-2,3- dimethylimidazoliriium p-toluenesulfontate, 1,3- didodecyl-Z-methylimidazolinium chloride, l-decyl- 2,3-dimethylimidazolinium iodide, l-decyl-2,3- dimethylimidazolinium bromide, l-tetradecyl-2,3- dimethylimidazolinium iodide, l-tetradecyl-2,3- dimethylimidazolinium hydroxide, l-dodecyl-Z-undecyl-3-methylimidazolinium methylsulfate, 1,3- dihexadecyl-2-heptadecylimidazolinium chloride, lhydroxyethyl-Z-methyl-3-dodecylimidazolinium p-toluenesulfonate, l,3-didodecyl-2-phenylimidazolinium chloride, l-dodecyl-2,4-dimethyl-3- benzylimidazolinium chloride, 1,3-dihexadecyl-2-phenyl-4-methyIimidazolinium chloride, l-vinyl-2-methyl- 3-dodecylimidazolinium chloride, l-vinyl-2-methyl-3- hexadecylimidazolinium chloride, l'allyl-2-methyl-3- dodecylimidazolinium chloride, l-(7-aminopropyl)-2- methyl-3-dodecylimidazolinium chloride, l-undecenyl- 2-octyl-3-ethylimidazolinium bromide, l-eicosyl-Z- eicosenyl-3-decylimidazolinium bromide, l-dodecyl-Z- methyl-3-benzylimidazolinium chloride, 1,3-dibenzyl- Z-methylimidazolinium chloride, 1,3-dibenzyl-2- methylimidazolinium hydroxide, l-benzyl-2-methyl-3- dodecylimidazolinium chloride, l-dodecyl-2-methyl-3- benzylimidazolinium chloride, l-butyl-2-heptyl-3- benzylimidazolinium chloride, l-tetradecyl-Z-methyl- 3-benzylimidazolinium bromide, l-dodecyl-Z-phenyl- 3-benzylimidazolinium bromide, l-benzyl-2-undecyl-3- methylimidazolinium methylsulfate, l-amyI-Z-undecyl- 3-benzylimidazolinium bromide, l-dodecyl-2,5- dimethyl-3-benzylimidazolinium chloride, l-dodecyl- 2-phenyl-3-benzyl-4-methylimidazolinium bromide, l-(2'-pyrimidinyl)-2,3-dimethylimidazolinium chloride, l,4-butylene-bis[ l -ethyl-3'- dodecylimidazolinium'(2')] dichloride, l,4-phenylenebis[ 1 '-dodeeyl-3 '-benzyl-4-methylimidazolinium- (2')] dichloride, l,4-phenylene-bis[ l -dodecyl-3- dibenzyl-4-methylimidazolinium-( 2')] dibromide, l,4- butylene-bis[2-ethyl-3'-dodecyl-4- methylimidazoliniumt 1)] dichloride, 1,4-butylenebis[2'-methyl-3-hydroxyethylimidazolinium-(1)] dichloride, l,2-ethylene-bis[2',3- dimethylimidazolinium-( l ')1 dichloride.

The water (e) ingredient can be added directly or in the form of metal salt hydrates into the fluoroelastomer composition, which metal salt hydrates are capable of providing water harmlessly in cure, such as MgSO .l- H O, CuSO,.5H O and FeSO,.7H O. As a metal compound which readily produces water by reacting it with hydrogen fluoride, metal hydroxides such as Mg(OH) Pb(OH) and Ca(OH) may be employed. In case of using these metal hydroxides, the addition of (b) ingredient may be omitted.

As the amount of the above ingredients to parts by weight of fluoroelastomer in the present invention. 2 to 30 parts, preferably 5 to 20 parts by weight of (b) ingredient, 0.5 to 5 parts, preferably 1 to 2 parts by weight of (c) ingredient and 0.2 to 10 parts, preferably 0.5 to 3 parts by weight of (d) ingredient respectively are suitably employed. In case the amount of (d) ingredient is less than the above range, the cure of the fluorolastomer composition tends to occur unsatisfactory. On the other hand, in case that of (d) ingredient is more than the above range, the elastic properties of the resultant fluororubber are liable to be reduced. The

amount of water being (e) ingredient may be 0.1 to l0 parts, preferably 0.5 to 5 parts by weight to 100 parts by weight offluoroelastomer. The amount of the metal compound varies according to the kind thereof, and in general it may be 0.5 to 30 parts, preferably 2 to 10 parts by weight to 100 parts by weight of fluoroelastomer.

In the present invention, filler such as carbon black. silica, clay, diatomaceous earth or talc may be further added into the composition of the invention in accordance with necessity. If necessary, 'one or more of a small amount of the conventional curing agent may be added into the composition of the invention unless the spirit of the present invention is lost. Moreover, plasticizer and colorant also may be added.

Thus obtained fluoroelastomer composition can be cured by a conventional process. For instant, the composition is milled by mixing rolls and the resultant compound is put into a mold and cured under pressure and then the resultant article is removed out of the mold, followed by curing it in an oven. In general, the press cure is carried out at a temperature of 100 to 200C. under a pressure of 20 to 100 kg./cm. for a period of 10 to 180 minutes, and the oven cure is carried out at a temperature of l50 to 300C. for a period of 0 to 30 hours. Other processes for cure, for instant, a process which the cure is carried out after pre-molding such as injection molding or extrusion molding; alternatively a process which a coating composition prepared by dissolving or dispersing the fluoroelastomer composition into a solvent such as ketones, e.g. methyl ethyl ketone, acetone and cyclohexanone, ethers, e.g. methyl ethyl ether, diethyl ether, dioxane and tetrahydrofuran, or a mixture thereof is applied on a surface of paper, fiber, film, sheet, board, tube, pipe, tank, big vessel or the other shaped articles (made by cellulose derivatives, synthetic resin, metal or the others) and then cured, may be carried out.

The fluoro-rubber obtained by the fluoroelastomer composition of the present invention has advantages such as an excellent heat resistance, a low temperature resistance and a chemical resistance as well as the fluoro-rubber obtained by a conventional fluoroelastomer composition, and further shows exellent properties above-mentioned, which can not be obtained by a conventional fluoroelastomer composition.

The present invention is more specifically described and explained by means of the following Examples which, however, are not intended to be limited. ln Examples, all parts and percentages are by weight except as otherwise noted.

REFERENCE EXAMPLE 1 A 3 liter stainless steel autoclave was charged with 1,000 parts of demineralized and deoxidized water. Air

within the autoclave was-thoroughly replaced with pure nitrogen gas and then nitrogen gas within the autoclave was thoroughly replaced with tetrafluoroethylene. The autoclave was charged with 96 parts of a monomer mixture consisting of 27.1 percent of vinylidene fluoride, 63.5 percent of hexafluoropropene and 9.4 percent of tetrafluoroethylene. The temperature was raised to 100C. with agitation and the polymerization was initiatedby adding 10 parts ofa 6 percent aqueous solution of ammonium persulfate under a pressure of 12 kg./cm

The polymer was obtained in a form of emulsion. A l percent aqueous solution of magnesium chloride was added to the autoclave to coagulate the polymer. The polymer was washed with water and dried to give 423 parts of colorless elastic terpolymer.

REFERENCE EXAMPLE 2 A 3 liter stainless steel autoclave provided with a magnetic stirrer was charged with l liter of deoxidized water and 0.3 g. of methylcellulose (50 cps.). After air within the autoclave was thoroughly replaced with pure nitrogen gas and then evacuated, the autoclave was charged with 300 cc. of l,l,2-trichloro-l,2,2- trifluoroethane, then with 300 g. ofa monomer mixture consisting of hexafluoropropene, vinylidene fluoride and tetrafluoroethylene in the molar ratio of 50.6:44.9:4.5 and kept at 40C. with agitation.

A 125 cc. tank cooled by dry ice was charged with 50 cc. of 1.97 percent solution of di(3,5,6-trichloro- 2,2,3,4,4,5,6,6-octafluorohexanoyl) peroxide in l,l,2- trichloro-l ,2,2-trifluoroethane, and the solution was introduced into the autoclave by nitrogen pressure to initiate polymerization.

Another 20 liter autoclave was charged with a monomer mixture for continuous charging consisting of hexafluoropropene, vinylidene fluoride and tetrafluoroethylene in the molar ratio of 20:68: I 2 and connected to the said autoclave. The monomer mixture was supplied to the autoclave so as to maintain a constant pressure between 9 to 10 kg./cm. G. Further, 50 cc. of the said initiator solution was additionally supplied, and polymerization for about 5 hours gave about 300 g. of a fluoroelastomer as small white granules.

izrzrerusrvcrz EXAMPLE 3 3 3 liter stainless steel autoclave provided with a magnetic stirrer was charged with 1 liter of deoxidized water and 0.3 g. of methylcellulose (50 cps.). After air within the autoclave was thoroughly replaced with pure nitrogen gas and then evacuated, the autoclave was charged with 300 cc. of l,l,2-trichloro-l,2,2- trifluoroethane, and then with 300 g. of a monomer dene fluoride in the molar ratio of 58:42. It was maintained at 30C. with agitation.

A 125 cc. tank cooled by dry ice was charged with 50 cc. of 1.97 percent solution of di(3,5,6-trichloro- 2,2,3,4,4,5,6,6-octafluorohexanoyl) peroxide in 1,1,2- trichloro-l ,2,2-trifluoroethane, and the solution was introduced into the autoclave by nitrogen pressure to initiate polymerization.

Another 20 liter stainless steel autoclave was charged with a monomer mixture for continuous charging consisting of hexafluoropropene and vinylidene fluoridein the molar ratio of 25:75 and connected to the said autoclave. The monomer mixture was supplied to the autoclave so as to maintain the polymerization pressure between 8 and 9 kg./cm. G. The polymerization was carried out for about 5 hours. Then, the residual monomers were purged off to give about l40 g. of a small granular fluoroelastomer.

EXAMPLES l .to 3

To a vinylidene fluoride-hexafluoropropene-tetrafluoroethylene terpolymer copolymerized in the molar ratio of 66.5:l6.0: l 7.5, which was previously obtained by Reference Example 1. was added medium thermal carbon, magnesium oxide. calcium hydroxide, hydroquinone and l,3-dibenzyl-2-methylimidazolium chloride with the amount showed in the following Table l. in order. The composition was milled by a mixing roll at a room temperature. and the resultant compounds were allowed to stand over night. After milling again. the composition was put into a mold and cured at a temperature of 170C. under a pressure of kg./cm. G. for a period of 30 minutes to give sheet and block, respectively. THe resultant was removed out of the mold and cured at a temperature of 230C. for a period of 24 hours (Example 1).

Modulus at lOO percent elongation, tensile strength, elongation and hardness of the obtained fluoro-rubber sheet and compression set of the obtained fluororubber block were measured. And further curing test of the composition was carried out and stresses after lapse of a fixed time was measured by using a curelasto meter.

Moreover the procedure of Example I was repeated except that l-dodecyl-2-methyl-3-benzylimidazolium chloride was employed instead of 1,3-dibenzyl-2- methylimidazolium chloride (Example 2), that water was further added (Example 3), that no quaternary ammonium compound was employed (Comparative Example l), and that N,N-dicinnamylidene-l ,6- hexanediamine was employed as a conventional curing agent instead of l,3-dibenzyl-2-methylimidazolium chloride and hydroquinone (Comparative Example 2). The amount employed and the result were shown in the mixture consisting of hexafluoropropene and vinyli- 55 following Table 1.

Table 1 Ingredients Fluoro- Magnesium Medium Calcium Hydroquil,3-dibenzyll-dodecyl-2- N,N-dicinna- Water elastomer ox|de thermal hydroxide none Z-methylimidamethyl-J-benmylidene- I .6-

carbon zolium chlorizylimidazoliuhexanediamine de m chloride Ex. l 20 10 2 l l Ex. 2 l00 2O 10 3 l l.5 Ex. 3 100 20 10 l 0.8 l 5 Corn. Ex. l l00 2O 10 2 l Com. Ex. 2 I00 20 15 3 Table l-(Yontinued Curing test properties 1 2 3 4 5 l l Modulus Tensile Elonga- Hard- Compression set min. min. min. min. min. min. min. min. at 100% strength tion ness 30C X 200C 24hr X 24hr s) g-l s/cm?) 0.45 0.60 0.80 1.75 3.35 3.65 3.70 3.70 68 155 180 78 20 0.60 0.65 0.75 1.60 2.50 3.30 3.40 3.40 88 150 160 82 21 0.70 1.40 1.90 2.25 2.55 3.50 4.00 81 159 170 82 12 25 not cured 0.50 0.70 1.10 1.40 1.80 2.70 3.05 3.10 50 180 290 76 33 35 NOTE amplitude of 3, and then stress is measured after the l. Modulus at 100 percent elongation, tensile strenglapse of the fixed time.

In and iongjtion are dmefasuredh with dtlimbbfell tesc: 15 EXAMPLE 4 pieces o. prepare rom t e samp es 0 cure sheet by using a universal tensile tester (UTM-lll type) The h? for cur'hg h Example h riepeatedifor made by Toyo Sokki Kabushiki Kaisha according to the the corhposmoh showh m the h Table provision of Japan Industrial Standard K 6301 Cone the curing test was carried out, which results are shown Spends to ASTM D 4]2 68' in Table 2. FIG. 1 shows the curing curves of Example 2. Hardness is measured by using a hardness tester Comparahve Examples 4 and 5 by Cure (Asker J type) made by Kobunshi Keiki Kabushiki lasto meter. As 15. clear from Table 2 and FIG. 1, the Sha. composition including l-dodecyl-2-methyl-3- 3 Compression set is measured with the test disk benzylimidazolium chloride of the present invention Samples prepared from the Samples of cured block, has an adequate induction period and an excellent procording to the provision of 11S K 6301 as follows: The h can he cureh F "h test samples are kept at and 200C under a parison with the compositions including imidazole per pression of 25 percent for 24 hours and then allowed se and its salts of hydrochloride as comparative Examto stand at a room temperature for 30 minutes for P measurement with a thickness gauge for rubber of Pea- 30 EXAMPLES 5 to 9 cock type made by Kabushiki Kaisha Ozaki Seisakush0. Compression set is calculated on the basis of a thick- The P f for Curing of p was repeated for ness of sample according to the following equation: the composltloh Show" the followmg Table 3 and h properties were measured. The results were shown in Compression set (7r) (I r )/(I 1 X 100 Table wherein t is thickness (mm.) before compression, t, is EXAMPLES 10 to 12 thickness (mm.) after compression and i is thickness Employing the fluoroelastomers obtained by Refer- (mm.) of spacer. ence Example 1 for Example 10, by Reference Exam 4. Curing test is carried out with the sample (34 mm. 40 ple 2 for Example 1 l and by Reference Example 3 for x 7 mm. X 2 mm.) by using a curelasto meter (JSR- Example 12, the process for curing of Example 1 was curelasto meter No. 11 Type). The test sample is put repeated for the composition shown in the following into a mold chamber and tested under the condition of Table 4 and the properties of the resultant rubber were temperature of 180C, frequency of6 c./min. and and measured. The results were shown in Table 4.

Table 2 Ingredients Fluoro- Magnesium Medium Calcium Hydroqui- 2-methyll-dodecyl-2- l-dodecyl-Z- l-dodecyl-2- elastooxide thermal hydroxide none imidazole methylimidamethylimldamethyl-S-benmer carbon zole zole hydrozylimidazolium chloride chloride Ex. 4 20 i0 3 l 1 Com.

Ex. 3 100 20 10 2 1 l Com. Ex. 4 100 20 10 2 l l Com. Ex. 5 I00 20 i0 2 l 1.2

Curing test 1 min. 2 min. 3 min. 4 min. 5 min. 10 min. 20min. 30 min.

not cured Table 3 ingredients Fluoro- Magnesium Medium Calcium Bisphenol Potassium l,3-dibenzyl-2- l-dodecyl-Z- Water elastomer oxide thermal hydroxide A salt of methylimidazomethyl-B-benzylcarbon bisphenol lium chloride imidazolium A chloride Ex. 5 I00 2O 2 2 l Ex. 6 100 10 2O 3 2 l EX. 7 100 ll) 2 I l Ex. 8 100 10 2O 2 l 2 Ex. 9 100 10 20 3 l Properties Modulus at 100 Tensile strength Elongation Hardness C X 24 hr 38855 3 2 2:

(kg/cm?) (kg/cm?) 75 I58 170 82 l2 2O 72 l5l 170 80 i3 21 62 I 180 78 l2 l9 6] I52 I 77 14 22 l80 SI 14 23 Table 4 Ingredients Fluoroelastomer Magnesium oxide Medium thermal Calcium 'hydr- Hydroquinone 1.3-dibercarbon oxide zyl-2- methylimiduzolium chloride Ex. I0 I00 IO 20 2 l 0.8 Ex. ll lOO IO 20 2 l 1 Ex. 12 I00 10 2O 2 l Properties Mod lus at 1 Tensile strength Elongation Hardness Compression set (kg/cm?) (kg/cm") 30C X 24 hr 200C X 24 hr 90 I61 I70 77 l l 2i 85 1 58 77 I2 23 98 I63 I60 87 ll 22 What IS Claimed is: I R4 R5 R5 R4 1. A fluoroelastomer composition consisting essentially of (a) a fluoroelastomer, (b) 2 to 30 parts of at N'B N N+R3 least one member selected from the group consisting of R2 m (3) a bivalent metal oxide, a bivalent metal hydroxide and a mixture of bivalent metal oxide or metal hydroxide with a metal salt of weak acid. (0) 0.5 to 5 parts of an aromatic polyhydroxy compound. (d) 0.2 to 10 parts of m H a quaternary ammonium compound having the general formula: am N ltn x- RT==\R4 RIN N+R3 X- R3 R3 R4 ""N N R4 in 1) I A- 2X- 60 R5 N N R5 5 or R1 R1 it: R, Rl N N1 R 65 RAF-Rd R5llR4 u: lwN N-B-N\/N+m 2X R5 N N Rn ll] R1 R R2 wherein R, is alkyl group having I to 20 carbon atoms, carbocyclic group. heterocyclic group having 1 to 3 nitrogen atoms or aralkyl group having 7 to 20 carbon atoms, R; is hydrogen, alkyl group having 1 to l2 carbon atoms, carbocyclic group, heterocyclic group having 1 to 3 nitrogen atoms, phenyl group, aralkyl group having 7 to l2 carbon atoms, alkoxyl group having 1 to 12 carbon atoms, benzyloxy group, hydroxyl group, carboxyl group, alkoxycarbonyl group, acyl group, benzoyl group or cyclohexylcarbonyl group, R is alkyl group having 1 to 20 carbon atoms or aralkyl group having 7 to 20 carbon atoms, R, and R are hydrogen or lower alkyl group, A is alkylene group or phenylene group, B is alkylene group, and X is an anion selected from the group consisting of a halide ion, hydroxylate ion, alkoxylate ion, phenoxide ion, carboxylate ion, sulfonate ion, sulfate ion, sulflte ion and carbonate ion, and (e) 0.l to 10 parts of water or 0.5 to 30 parts ofa metal compound which produces water by reacting with hydrogen fluoride, said parts of (b), (c), (d) and (e) being parts by weight per 100 parts of (a).

2. The composition of claim 1, wherein said quaternary ammonium compound is present in an amount of 0.5 to 3 parts by weight to I parts by weight of fluoroelastomer.

3. The composition of claim 1, wherein said quaternary ammonium salt is a member selected from the group consisting of l,3-dibenzyl-2-methylimidazolium chloride and l-dodecyl-2-methyl-3-benzylimidazolium chloride.

4. The composition of claim 1, wherein said water is added in an amount of 0.5 to parts by weight to 100 parts by weight of fluoroelastomer.

5. The composition of claim 1, wherein said metal compound is added in an amount of 2 to parts by weight to 100 parts by weight of fluoroelastomer.

6. The composition of claim 1, wherein said water is in the form of metal salt hydrate selected from the 14 group consisting of MgSO,.7H-,O, CuSO,.5H,O and Fe- SO,.7H O.

7. The composition of claim I, wherein said (b) ingredient is added in an amount of 5 to 20 parts by weight to parts by weight of fluoroelastomer.

8. The composition of claim 1, wherein said aromatic polyhydroxy compound is added in an amount of l to 2 parts by weight to 100 parts by weight of fluoroelastomer.

9. The composition of claim 1, wherein said polyhydroxy aromatic compound is hydroquinone, 2,2-bis(4- hydroxyphenylJpropane, 2,2-bis(4-hydroxyphenyl)butane or 2,2-bis(4-hydroxyphenyl)perfluoropropane.

10. The composition of claim 1, wherein said fluoroelastomer is a copolymer of vinylidene fluoride and hexafluoropropane.

11. The composition of claim 1, wherein said fluoroelastomer is a terpolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropene.

12. The composition of claim 10, wherein said fluoroelastomer is a copolymer which composition is in the ratio of vinylidene fluoride and hexafluoropropene bening 92:8 to 66:34 by mole.

l3. The composition of claim 11, wherein said fluoroelastomer is a terpolymer which composition is in rectangular area formed by the following 4 ratios of vinylidene fluoride, tetrafluoroethylene and hexafluoropropene being 85.7:5:9.3, 59.7:5:35.3, 28:30:42 and 54:30:16 by mole.

14. The composition of claim 1 wherein the fluoroelastomer (a) is a copolymer of vinylidene fluoride and at least one fluoro-olefin.

15. The composition of claim 14 wherein the said fluoro-olefin is hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoro (methyl vinyl ether) or perfluoro (propyl vinyl ether).

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 864,298 D d February 4, 1975 0 Inventor s YUTAKA KOMETANI et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Table 1, columns 7 and 8, the second heading from the left, read Medium thermal carbon instead of "Magnesium oxide" Table 1, columns 7 and 8 the third heading from the left, read Magnesium oxide instead of "Medium thermal carbon".

Table 2 columns 9 and 10, the second heading from the left, read Medium thermal carbon instead of "Magnesium oxide".

Table 2 columns 9 and 10, the third heading from the left, read Magnesium oxide instead of "Medium thermal carbon".

Column 2, formula (3) should read as follows:

\ 2X (3) R N N B N N R Q f 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 864,298 Dated February 4, 1975 Inv nt fl KOMETANI et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 16 read p-toluenesulfonate instead of "p-toluenesulfotate" Column 7, line 28 read 30C. instead of "40C.".

Column 10, line 25 read time instead of "period".

Column 10, line 28 read hydrogenchloride instead of "hydrochloride".

Column 12, formula (4) should read as follows:

Signed and Sealed this twenty-sixth Day Of August 1975 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner uj'PatenIs and Trademarks 

1. A FLUORELASTOMER COMPOSITION CONSISTING ESSENTIALLY OF (A) A FLUOROCLASTOMER, (B) 2 TO 30 PARTS OF AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF A BIVALENT METAL OXIDE, A BIVALENT METAL HYDROXIDE AND A MIXTURE OF BIVALENT METAL OXIDE OR METAL HYDROXIDE WITH A METAL SALT OF WEAK ACID, (C) 0.5 TO 5 PARTS OF AN AROMATIC POLYHYDOXY COMPOUND, (D) 0.2 TO 10 PARTS OF A QUATERNARY AMMONIUM COMPOUND HAVING THE GENERAL FORMULA: GROUP HAVING 1 TO 12 CARBON ATOMS, BENZYLOXY GROUP, HYDROXYL GROUP, CARBOXYL GROUP, ALKOXYCARBONYL GROUP, ACYL GROUP, BENZOYL GROUP OR CYCLOHEXYLCARBONYL GROUP, R3 IS ALKYL GROUP HAVING 1 TO 20 CARBON ATOMS OR ARALKYL GROUP HAVING 7 TO 20 CARBON ATOMS, R4 AND R5 ARE HYDROGEN OR LOWER ALKYL GROUP, A IS ALKYLENE GROUP OR PHENYLENE GROUP, B IS ALKYLENE GROUP, AND X- IS AN ANION SELECTED FROM THE GROUP CONSISTING OF A HALIDE ION, HYDROXYLATE ION, ALKOYLATE ION, PHENOXIDE ION, CARBOXYLATE ION, SULFONATE ION, SULFATE ION, SULFITE ION AND CARBONATTE ION, AND (E) 0.1 TO 10 PARTS OF WATER OR 0.5 TO 30 PARTS OF A METAL COMPOUND WHICH PRODUCES WATER BY REACTING WITH HYDROGEN FLUORIDE, SAID PARTS OF (B), (C), (D) AND (E) BEING PARTS BY WEIGHT PER 100 PARTS OF (A).
 2. The composition of claim 1, wherein said quaternary ammonium compound is present in an amount of 0.5 to 3 parts by weight to 100 parts by weight of fluoroelastomer.
 3. The composition of claim 1, wherein said quaternary ammonium salt is a member selected from the group consisting of 1,3-dibenzyl-2-methylimidazolium chloride and 1-dodecyl-2-methyl-3-benzylimidazolium chloride.
 4. The composition of claim 1, wherein said water is added in an amount of 0.5 to 5 parts by weight to 100 parts by weight of fluoroelastomer.
 5. The composition of claim 1, wherein said metal compound is added in an amount of 2 to 10 parts by weight to 100 parts by weight of fluoroelastomer.
 6. The composition of claim 1, wherein said water is in the form of metal salt hydrate selected from the group consisting of MgSO4.7H2O, CuSO4.5H2O and FeSO4.7H2O.
 7. The composition of claim 1, wherein said (b) ingredient is added in an amount of 5 to 20 parts by weight to 100 parts by weight of fluoroelastomer.
 8. The composition of claim 1, wherein said aromatic polyhydroxy compound is added in an amount of 1 to 2 parts by weight to 100 parts by weight of fluoroelastomer.
 9. The composition of claim 1, wherein said polyhydroxy aromatic compound is hydroquinone, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane or 2,2-bis(4-hydroxyphenyl)perfluoropropane.
 10. The composition of claim 1, wherein said fluoroelastomer is a copolymer of vinylidene fluoride and hexafluoropropane.
 11. The composition of claim 1, wherein said fluoroelastomer is a terpolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropene.
 12. The composition of claim 10, wherein said fluoroelastomer is a copolymer which composition is in the ratio of vinylidene fluoride and hexafluoropropene bening 92:8 to 66:34 by mole.
 13. The composition of claim 11, wherein said fluoroelastomer is a terpolymer which composition is in rectangular area formed by the following 4 ratios of vinylidene fluoride, tetrafluoroethylene and hexafluoropropene being 85.7:5:9.3, 59.7: 5:35.3, 28:30:42 and 54:30:16 by mole.
 14. The composition of claim 1 wherein the fluoroelastomer (a) is a copolymer of vinylidene fluoride and at least one fluoro-olefin.
 15. The composition of claim 14 wherein the said fluoro-olefin is hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoro (methyl vinyl ether) or perfluoro (propyl vinyl ether). 